Today, live field production of 3D stereoscopic images typically requires a two-camera rig using image splitting to produce two images—a left image and a right image. The two cameras must be setup and registered to each other to eliminate geometric or spatial mismatches, such as 1) vertical deviation, 2) angle deviation (other than desired parallax), 3) rotation error, 4) zoom or focal length mismatch, and 5) scene composition. Also, it is required that the two cameras be adjusted to mitigate mismatches in 6) brightness/contrast (aperture or gain) and color balance between the cameras or imagers as well as temporal mistiming.
Adjusting the cameras to match and eliminate one or more of these differences is currently done by such methods as: a) looking at a picture monitor of a split screen of the two images for side-by-side comparison; b) using a checkerboard pattern where adjacent squares are alternately switched between the left and right images to facilitate matching on a single picture, or c) using a waveform monitor or vector display to precisely match signal levels and color balance of the two cameras to mitigate the mismatching in brightness/contrast and color balance.
U.S. Pat. No. 5,307,087, issued to Daniel G. Baker on Apr. 26, 1994 entitled “Three-Dimensional RGB Component Vector Display”, provides a three-dimensional display for a standard two-dimensional video display by combining two pairs of combination signals, such as green and blue components and green and red components. The two combination signals are input alternately to the inputs of a vector display device to provide a symmetrical display about an axis of symmetry, where one-half characterizes the blue component, the other half characterizes the red component, and both halves characterize the green component. The resulting “Diamond” display includes a graticule for each half to define a color gamut region for the three color components so a user can see whether a color video signal represents a valid color space in RGB.
What is desired is a method and display that is easy to use and understand that allows precise matching of signal levels due to camera color balance, aperture (gain) and timing mismatch between left and right images so a user may readily provide stereoscopic image registration and color balance evaluation for stereoscopic images produced by a two-camera stereoscopic system. It also should provide indication of optimal geometric alignment so any mismatch may be nullified by adjusting relative left and right camera tilt, rotation and zoom without reference to particular image segments on a picture display.